High purity tantalum, products containing the same, and methods of making the same

ABSTRACT

High purity tantalum metals and alloys containing the same are described. The tantalum metal preferably has a purity of at least 99.995 % and more preferably at least 99.999%. In addition, tantalum metal and alloys thereof are described, which either have a grain size of about 50 microns or less, or a texture in which a (100) intensity within any 5% increment of thickness is less than about 15 random, or an incremental log ratio of (111):(100) intensity of greater than about −4.0, or any combination of these properties. Also described are articles and components made from the tantalum metal which include, but are not limited to, sputtering targets, capacitor cans, resistive film layers, wire, and the like. Also disclosed is a process for making the high purity metal which includes the step of reacting a salt-containing tantalum with at least one compound capable of reducing this salt to tantalum powder and a second salt in a reaction container. The reaction container or liner in the reaction container and the agitator or liner on the agitator are made from a metal material having the same or higher vapor pressure of melted tantalum. The high purity tantalum preferably has a fine and uniform microstructure.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to metals, in particular tantalum,and products made from tantalum as well as methods of making andprocessing the tantalum.

[0002] In industry, there has always been a desire to form higher puritymetals for a variety of reasons. With respect to tantalum, higher puritymetals are especially desirable due to tantalum's use as a sputteringtarget and its use in electrical components such as capacitors. Thus,impurities in the metal can have an undesirable effect on the propertiesof the articles formed from the tantalum.

[0003] When tantalum is processed, the tantalum is obtained from ore andsubsequently crushed and the tantalum separated from the crushed orethrough the use of an acid solution and density separation of the acidsolution containing the tantalum from the acid solution containingniobium and other impurities. The acid solution containing the tantalumis then crystallized into a salt and this tantalum containing salt isthen reacted with pure sodium in a vessel having an agitator typicallyconstructed of nickel alloy material, wherein tungsten or molybdenum ispart of the nickel alloy. The vessel will typically be a double walledvessel with pure nickel in the interior surface. The salt is thendissolved in water to obtain tantalum powder. However, during suchprocessing, the tantalum powder is contaminated by the various surfacesthat it comes in contact with such as the tungsten and/or molybdenumcontaining surfaces. Many contaminants can be volatized duringsubsequent melting, except highly soluble refractory metals (e.g., Nb,Mo, and W). These impurities can be quite difficult or impossible toremove, thus preventing a very high purity tantalum product.

[0004] Accordingly, there is a desire to obtain higher purity tantalumproducts which substantially avoid the contaminations obtained duringthe processing discussed above. Also, there is a desire to have atantalum product having higher purity, a fine grain size, and/or auniform texture. Qualities such as fine grain size can be an importantproperty for sputtering targets made from tantalum since fine grain sizecan lead to improved uniformity of thickness of the sputtered depositedfilm. Further, other products containing the tantalum having fine grainsize can lead to improved homogeneity of deformation and enhancement ofdeep drawability and stretchability which are beneficial in makingcapacitors cans, laboratory crucibles, and increasing the lethality ofexplosively formed penetrators (EFP's). Uniform texture in tantalumcontaining products can increase sputtering efficiency (e.g., greatersputter rate) and can increase normal anisotropy (e.g., increased deepdrawability), in preform products.

SUMMARY OF THE PRESENT INVENTION

[0005] A feature of the present invention is to provide a high puritytantalum product exhibiting a fine grain structure and/or uniformtexture.

[0006] Another feature of the present invention is to provide articles,products, and/or components containing the high purity tantalum.

[0007] An additional feature of the present invention is to provideprocesses to make the high purity tantalum product as well as thearticles, products and/or components containing the high puritytantalum.

[0008] Additional features and advantages of the present invention willbe set forth in part in the description which follows, and in part willbe apparent from the description, or may be learned by practice of thepresent invention. The objectives and other advantages of the presentinvention will be realized and attained by means of the elements andcombinations particularly pointed out in the description and appendedclaims.

[0009] To achieve these and other advantages, and in accordance with thepurpose of the present invention, as embodied and broadly describedherein, the present invention relates to tantalum metal having a purityof at least 99.995% and more preferably at least 99.999%. The tantalummetal preferably has a fine grain structure and/or uniform texture.

[0010] The present invention further relates to an alloy or mixturecomprising tantalum, wherein the tantalum present in the alloy ormixture has a purity of at least 99.995% and more preferably at least99.999%. The alloy or mixture (e.g., at least the tantalum present inthe alloy or mixture) also preferably has a fine grain structure and/oruniform texture.

[0011] The present invention also relates to a high purity tantalum,e.g., suitable for use as a sputtering target, having a fullyrecrystallized grain size with an average grain size of about 150 μm orless and/or having a primary (111)-type texture substantially throughoutthe thickness of the tantalum and preferably throughout the entirethickness of the tantalum metal and/or having an absence of strong (100)texture bands within the thickness of the tantalum.

[0012] The present invention further relates to manufacturing plate andsheet from the above-mentioned tantalum by flat-forging the tantalum,machining into rolling slabs, annealing rolling slabs, rolling intoplate or sheet, then annealing the plate or sheet. Final products suchas sputtering targets can be then machined from the annealed plate orsheet.

[0013] The present invention also relates to a sputtering targetcomprising the above-described tantalum and/or alloy. The sputteringtarget can also be formed by radial forging and subsequent roundprocessing to produce billets or slugs, which are then forged and rolledto yield discs, which can then be machined and annealed.

[0014] The present invention further relates to resistive films andcapacitors comprising the above-described tantalum and/or alloy.

[0015] The present invention also relates to articles, components, orproducts which comprise at least in part the above-described tantalumand/or alloy.

[0016] Also, the present invention relates to a process of making theabove-described tantalum which involves reacting a salt-containingtantalum with pure sodium or other suitable salt in a reactive containeror pot and an agitator which both are made from or have a linercomprising a metal or alloy thereof which has the same or higher vaporpressure as tantalum at the melting point of tantalum.

[0017] The present invention further relates to processing tantalumpowder by melting the tantalum powder in a high vacuum of 10⁻² torr ormore. The pressure above the melt is lower than the vapor pressures ofthe impurities existing in the tantalum. Preferably, the melting of thetantalum powder is accomplished by electron beam melting.

[0018] It is to be understood that both the foregoing generaldescription and the following detailed description are exemplary andexplanatory only and are intended to provide further explanation of thepresent invention, as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] FIGS. 1(A-B)-11(A-B) are graphs and corresponding data relatingto texture gradient (incremental thickness vs. random) and log ratio(111):(100) gradients (incremental thickness vs. Ln (111/100)) of highpurity tantalum plates of the present invention.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

[0020] The present invention relates to a tantalum metal having a purityof at least 99.995%. Preferably, the tantalum metal has a purity of atleast 99.999% and can range in purity from about 99.995% to about99.999% or more. Other ranges include about 99.998% to about 99.999% andfrom about 99.999% to about 99.9992% and from about 99.999% to about99.9995%. The present invention further relates to a metal alloy whichcomprises the high purity tantalum metal, such as a tantalum based alloyor other alloy which contains the high purity tantalum as one of thecomponents of the alloy.

[0021] The impurities that may be present in the high purity tantalummetal are less than or equal to 0.005% and typically comprise otherbody-centered cubic (bcc) refractory metals of infinite solubility intantalum, such as niobium, molybdenum, and tungsten.

[0022] The tantalum metal and alloys thereof containing the tantalummetal preferably have a texture which is advantageous for particular enduses, such as sputtering. In other words, when the tantalum metal oralloy thereof is formed into a sputtering target having a surface andthen sputtered, the texture of the tantalum metal in the presentinvention leads to a sputtering target which is easily sputtered and,very few if any areas in the sputtering target resist sputtering.Further, with the texture of the tantalum metal of the presentinvention, the sputtering of the sputtering target leads to a veryuniform sputtering erosion thus leading to a sputtered film which istherefore uniform as well. It is preferred that the tantalum having anypurity, but preferably a purity of at least about 99.995%, has a grainsize of about 150 microns or less. Preferably, the tantalum metal is atleast partially recrystallized, and more preferably at least about 80%of the tantalum metal is recrystallized and even more preferably atleast about 98% of the tantalum metal is recrystallized. Mostpreferably, the tantalum metal is fully recrystallized.

[0023] Also, it is preferred that the tantalum metal have a finetexture. More preferably the texture is such that the (100) peakintensity within any 5% incremental thickness of the tantalum is lessthan about 15 random, and/or has a natural log (Ln) ratio of (111):(100)center peak intensities within the same increment greater than about−4.0 (i.e., meaning, −4.0, −3.0, −2.0, −1.5, −1.0 and so on) or has boththe (100) centroid intensity and the ratio. The center peak intensity ispreferably from about 0 random to about 10 random, and more preferablyis from about 0 random to about 5 random. Other (100) centroid intensityranges include, but are not limited to, from about 1 random to about 10random and from about 1 random to about 5 random. Further, the log ratioof (111):(100) center peak intensities is from about −4.0 to about 15and more preferably from about −1.5 to about 7.0. Other suitable rangesof log ratios, include, but are not limited to, about −4.0 to about 10,and from about −3.0 to about 5.0. Most preferably, the tantalum metalhas the desired purity of at least about 99.995% and the preferred grainsize and preferred texture with regard to the (100) incrementalintensity and the (111):(100) ratio of incremental centroid intensities.The method and equipment that can be used to characterize the textureare described in Adams et al., Materials Science Forum, Vol. 157-162(1994), pp. 31-42; Adams et al., Metallurgical Transactions A, Vol 24A,April 1993-No. 4, pp.819-831; Wright et al., International AcademicPublishers, 137 Chaonei Dajie, Beijing, 1996 (“Textures of Material:Proceedings of the Eleventh International Conference on Textures ofMaterials);Wright, Journal of Computer-Assisted Microscopy, Vol. 5, No.3 (1993), all incorporated in their entirety by reference herein.

[0024] The high purity tantalum metal of the present invention can beused in a number of areas. For instance, the high purity tantalum metalcan be made into a sputtering target or into chemical energy (CE)munition warhead liner which comprises the high purity metal. The highpurity metal can also be used and formed into a capacitor anode or intoa resistive film layer. The tantalum metal of the present invention canbe used in any article or component which conventional tantalum is usedand the methods and means of making the various articles or componentscontaining the conventional tantalum can be used equally here inincorporating the high purity tantalum metal into the various articlesor components. For instance, the subsequent processing used in makingsputtering targets, such as the backing plate, described in U.S. Pat.Nos. 5,753,090, 5,687,600, and 5,522,535 can be used here and thesepatents are incorporated in their entirety by reference herein.

[0025] Generally, a process that can be used to make the high puritytantalum metal of the present invention involves a refining process, avacuum melting process, and a thermal mechanical process. In thisprocess or operation, the refining process involves the steps ofextracting tantalum metal preferably in the form a powder from orecontaining tantalum and preferably the ore-containing tantalum selectedhas low amounts of impurities, especially, low amounts of niobium,molybdenum, and tungsten. More preferably, the amount of niobium,molybdenum, and tungsten is below about 10 ppm, and most preferably isbelow about 8 ppm. Such a selection leads to a purer tantalum metal.After the refining process, the vacuum melting process is used to purgelow melting point impurities, such as alkyde and transition metals fromthe tantalum while consolidating the tantalum material into a fullydense, malleable ingot. Then, after this process, a thermal mechanicalprocess can be used which can involve a combination of cold working andannealing of a tantalum which further ensures that the preferred grainsize and/or preferred texture and uniformity are achieved, if desired.

[0026] The high purity tantalum metal preferably may be made by reactinga salt-containing tantalum with at least one agent (e.g., compound orelement) capable of reducing this salt to the tantalum metal and furtherresults in the formation of a second salt in a reaction container. Thereaction container can be any container typically used for the reactionof metals and should withstand high temperatures on the order of about800° C. to about 1,200° C. For purposes of the present invention, thereaction container or the liner in the reaction container, which comesin contact with the salt-containing tantalum and the agent capable ofreducing the salt to tantalum, is made from a material having the sameor higher vapor pressure as tantalum at the melting point of thetantalum. The agitator in the reaction container can be made of the samematerial or can be lined as well. The liner can exist only in theportions of the reaction container and agitator that come in contactwith the salt and tantalum. Examples of such metal materials which canform the liner or reaction container include, but are not limited to,metal-based materials made from nickel, chromium, iron, manganese,titanium, zirconium, hafnium, vanadium, ruthenium, cobalt, rhodium,palladium, platinum, or any combination thereof or alloy thereof as longas the alloy material has the same or higher vapor pressure as themelting point of tantalum metal. Preferably, the metal is a nickel or anickel-based alloy, a chromium or a chromium-based alloy, or an iron oran iron-based alloy. The liner, on the reaction container and/oragitator, if present, typically will have a thickness of from about 0.5cm to about 3 cm. Other thicknesses can be used. It is within the boundsof the present invention to have multiple layers of liners made of thesame or different metal materials described above.

[0027] The salt-containing tantalum can be any salt capable of havingtantalum contained therein such as a potassium-fluoride tantalum. Withrespect to the agent capable of reducing the salt to tantalum and asecond salt in the reaction container, the agent which is capable ofdoing this reduction is any agent which has the ability to result inreducing the salt-containing tantalum to just tantalum metal and otheringredients (e.g. salt(s)) which can be separated from the tantalummetal, for example, by dissolving the salts with water or other aqueoussources. Preferably, this agent is sodium. Other examples include, butare not limited to, lithium, magnesium, calcium, potassium, carbon,carbon monoxide, ionic hydrogen, and the like. Typically, the secondsalt which also is formed during the reduction of the salt-containingtantalum is sodium fluoride. Details of the reduction process which canbe applied to the present invention in view of the present applicationare set forth in Kirk-Othmer, Encyclopedia of Chemical Technology,3^(rd) Edition, Vol 22, pp. 541-564, U.S. Pat. Nos. 2,950,185;3,829,310; 4,149,876; and 3,767,456. Further details of the processingof tantalum can be found in U.S. Pat. Nos. 5,234,491; 5,242,481; and4,684,399. All of these patents and publications are incorporated intheir entirety by reference herein.

[0028] The above-described process can be included in a multi-stepprocess which can begin with low purity tantalum, such as ore-containingtantalum. One of the impurities that can be substantially present withthe tantalum is niobium. Other impurities at this stage are tungsten,silicon, calcium, iron, manganese, etc. In more detail, low puritytantalum can be purified by mixing the low purity tantalum which hastantalum and impurities with an acid solution. The low purity tantalum,if present as an ore, should first be crushed before being combined withan acid solution. The acid solution should be capable of dissolvingsubstantially all of the tantalum and impurities, especially when themixing is occurring at high temperatures.

[0029] Once the acid solution has had sufficient time to dissolvesubstantially, if not all, of the solids containing the tantalum andimpurities, a liquid solid separation can occur which will generallyremove any of the undissolved impurities. The solution is furtherpurified by liquid-liquid extraction. Methyl isobutyl ketone (MIBK) canbe used to contact the tantalum rich solution, and deionized water canbe added to create a tantalum fraction. At this point, the amount ofniobium present in the liquid containing tantalum is generally belowabout 25 ppm.

[0030] Then, with the liquid containing at least tantalum, the liquid ispermitted to crystallize into a salt with the use of vats. Typically,this salt will be a potassium tantalum fluoride salt. More preferably,this salt is K₂TaF₇. This salt is then reacted with an agent capable ofreducing the salt into 1) tantalum and 2) a second salt as describedabove. This compound will typically be pure sodium and the reaction willoccur in a reaction container described above. As stated above, thesecond salt byproducts can be separated from the tantalum by dissolvingthe salt in an aqueous source and washing away the dissolved salt. Atthis stage, the purity of the tantalum is typically 99.50 to 99.99% Ta.

[0031] Once the tantalum powder is extracted from this reaction, anyimpurities remaining, including any contamination from the reactioncontainer, can be removed through melting of the tantalum powder.

[0032] The tantalum powder can be melted a number of ways such as avacuum arc remelt or an electron beam melting. Generally, the vacuumduring the melt will be sufficient to remove substantially any existingimpurities from the recovered tantalum so as to obtain high puritytantalum. Preferably, the melting occurs in a high vacuum such as 10⁻⁴torr or more. Preferably, the pressure above the melted tantalum islower than the vapor pressures of the metal impurities in order forthese impurities, such as nickel and iron to be vaporized. The diameterof the cast ingot should be as large as possible, preferably greaterthan 9½ inches. The large diameter assures a greater melt surface tovacuum interface which enhances purification rates. In addition, thelarge ingot diameter allows for a greater amount of cold work to beimparted to the metal during processing, which improves the attributesof the final products. Once the mass of melted tantalum consolidates,the ingot formed will have a purity of 99.995% or higher and preferably99.999% or higher. The electron beam processing preferably occurs at amelt rate of from about 300 to about 800 lbs. per hour using 20,000 to28,000 volts and 15 to 40 amps, and under a vacuum of from about 1×10⁻³to about 1×10⁻⁶ Torr. More preferably, the melt rate is from about 400to about 600 lbs. per hour using from 24,000 to 26,000 volts and 17 to36 amps, and under a vacuum of from about 1×10⁻⁴ to 1×10⁻⁵ Torr. Withrespect to the VAR processing, the melt rate is preferably of 500 to2,000 lbs. per hour using 25-45 volts and 12,000 to 22,000 amps under avacuum of 2×10⁻² to 1×10⁻⁴ Torr, and more preferably 800 to 1200 lbs.per hour at from 30 to 60 volts and 16,000 to 18,000 amps, and under avacuum of from 2×10⁻² to 1×10⁻⁴ Torr.

[0033] The high purity tantalum ingot can then be thermomechanicallyprocessed to produce the high purity tantalum containing product. Thefine, and preferably fully recrystallized, grain structure and/oruniform texture is imparted to the product through a combination of coldand/or warm working and in-process annealing. The high purity tantalumproduct preferably exhibits a uniform texture of mixed or primary (111)throughout its thickness as measured by orientation imaging microscopy(OIM) or other acceptable means. With respect to thermomechanicalprocessing, the ingot can be subjected to rolling and/or forgingprocesses and a fine, uniform microstructure having high purity can beobtained. The high purity tantalum has an excellent fine grain sizeand/or a uniform distribution. The high purity tantalum preferably hasan average recrystallized grain size of about 150 microns or less, morepreferably about 100 microns or less, and even more preferably about 50microns or less. Ranges of suitable average grain sizes include fromabout 25 to about 150 microns; from about 30 to about 125 microns, andfrom about 30 to about 100 microns.

[0034] The resulting high purity metal of the present invention,preferably has 10 ppm or less metallic impurities and preferably 50 ppmor less O₂, 25 ppm or less N₂, and 25 ppm or less carbon. If a puritylevel of about 99.995 is desired, than the resulting high purity metalpreferably has metallic impurities of about 50 ppm or less, andpreferably 50 ppm or less O₂, 25 ppm or less N₂, and 25 ppm or lesscarbon.

[0035] With respect to taking this ingot and forming a sputteringtarget, the following process can be used. In one embodiment, thesputtering target made from the high purity tantalum metal can be madeby mechanically or chemically cleaning the surfaces of the tantalummetal, wherein the tantalum metal has a sufficient startingcross-sectional area to permit the subsequent processing steps describedbelow. Preferably the tantalum metal has a cross-sectional area of atleast 9½ inches or more. The next step involves flat forging thetantalum metal into one or more rolling slabs. The rolling slab(s) has asufficient deformation to achieve substantially uniformrecrystallization after the annealing step immediately following thisstep as described below. The rolling slab(s) is then annealed in vacuumand at a sufficient temperature to achieve at least partialrecystallization of the rolling slab(s). Preferred annealingtemperatures and times are set forth below and in the examples. Therolling slab(s) is then subjected to cold or warm rolling in both theperpendicular and parallel directions to the axis of the startingtantalum metal (e.g., the tantalum ingot) to form at least one plate.The plate is then subjected to flattening (e.g., level rolling). Theplate is then annealed a final time at a sufficient temperature and fora sufficient time to have an average grain size of equal to or less thanabout 150 microns and a texture substantially void of (100) texturalbands. Preferably, no (100) textural bands exist. The plate can then bemechanically or chemically cleaned again and formed into the sputteringtarget having any desired dimension. Typically, the flat forging willoccur after the tantalum metal is placed in air for at least about 4hours at temperatures ranging from ambient to about 370° C. Also,preferably before cold rolling, the rolling slabs are annealed at atemperature (e.g., from about 950° C. to about 1500° C.) and for a time(e.g., from about ½ hour to about 8 hours) to achieve at least partialrecrystallization of the tantalum metal. Preferably the cold rolling istransverse rolling at ambient temperatures and the warm rolling is attemperatures of less than about 370° C.

[0036] With respect to annealing of the tantalum plate, preferably thisannealing is in a vacuum annealing at a temperature and for a timesufficient to achieve complete recrystallization of the tantalum metal.The examples in this application set forth further preferred detailswith respect to this processing.

[0037] Another way to process the tantalum metal into sputtering targetsinvolves mechanically or chemically clean surfaces of the tantalum metal(e.g., the tantalum ingot), wherein the tantalum metal has a sufficientstarting cross-sectional area to permit the subsequent processing asdescribed above. The next step involves round forging the tantalum metalinto at least one rod, wherein the rod has sufficient deformation toachieve substantially uniform recrystallization either after theannealing step which occurs immediately after this step or the annealingstep prior to cold rolling. The tantalum rod is then cut into billetsand the surfaces mechanically or chemically cleaned. An optionalannealing step can occur afterwards to achieve at least partialrecrystallization. The billets are then axially forged into preforms.Again, an optional annealing step can occur afterwards to achieve atleast partial recrystallization. However, at least one of the optionalannealing steps or both are done. The preforms are then subjected tocold rolling into at least one plate. Afterwards, the surfaces of theplate(s) can be optionally mechanically or chemically clean. Then, thefinal annealing step occurs to result in an average grain size of about150 microns or less and a texture substantially void of (100) texturalbands, if not totally void of (100) textural bands. The round forgingtypically occurs after subjecting the tantalum metal to temperatures ofabout 370° C. or lower. Higher temperatures can be used which results inincreased oxidation of the surface. Preferably, prior to forging thebillets, the billets are annealed. Also, the preforms, prior to coldrolling can be annealed. Typically, these annealing temperatures will befrom about 900° C. to about 1200° C. Also, any annealing is preferablyvacuum annealing at a sufficient temperature and for a sufficient timeto achieve recrystallization of the tantalum metal.

[0038] Preferably, the sputtering targets made from the high puritytantalum have the following dimensions: a thickness of from about 0.080to about 1.50″, and a surface area from about 7.0 to about 1225 squareinches.

[0039] The high purity tantalum preferably has a primary or mixed (111)texture, and a minimum (100) texture throughout the thickness of thesputtering target, and is sufficiently void of (100) textural bands.

[0040] The present invention will be further clarified by the followingexamples, which are intended to be purely exemplary of the presentinvention.

EXAMPLES Example 1

[0041] Numerous sublots of sodium-reduced commercial-grade tantalumpowder, each weighing about 200-800 lbs., were chemically analyzed forsuitability as 99.999% Ta feedstock for electron beam melting.Representative samples from each powder lot were analyzed by GlowDischarge Mass Spectrometry (GDMS): powder sublots having combinedniobium (Nb), molybdenum (Mo), and tungsten (W) impurity content lessthan 8 ppm were selected for melting.

[0042] The selected Ta powder sublots were then blended in a V-coneblender to produce a homogeneous 4000 pound powder master lot, which wasagain analyzed by GDMS to confirm purity. Next, the powder was coldisostatically pressed (CIP'ed) into green logs approximately 5.5″-6.5″in diameter, each weighing nominally 300 pounds. The pressed logs werethen degassed by heating at 1450° C. for 2 hours at a vacuum level ofabout 10⁻³-10⁻⁵ torr. For this operation, the logs were covered withtantalum sheets to prevent contamination from the furnace elements.

[0043] The degassed logs were then side fed into a 1200 395 KW EBfurnace and drip melted at a rate of 400 lbs./hr. into a 10″water-cooled copper crucible under a vacuum less than 10⁻³ torr. Oncecooled, the resulting first-melt ingot was inverted, hung in the samefurnace, and remelted using the same EB melting parameters. The 2^(nd)melt ingot was again inverted and remelted a third time, but into a 12″crucible at a melt rate of 800 lbs./hr.

[0044] A sample was taken from the sidewall of the resulting ingot forchemical analysis by Glow Discharge Mass Spectrometry (GDMS). Resultsconfirmed that the Ta ingot was 99.9992% pure.

Example 2

[0045] A potassium fluotantalate (K₂TaF₇) was obtained and upon sparksource mass spec analysis, the K₂TaF₇ exhibited 5 ppm or less niobium.Levels of Mo and W were also analyzed by spectrographic detection andlevels were below 5 ppm for Mo and below 100 ppm for W. In particular,the K₂TaF₇ had levels of Nb of 2 ppm or less, of Mo of less than 1 ppmand of W of less than or equal to 2 ppm. In each sample, the totalrecorded amount of Nb, Mo, and W was below 5 ppm. Four lots of 2,200lbs. each were analyzed.

[0046] One of the lots was transferred to KDEL reactor which used a purenickel vessel and a Hastelloy X agitator. The Hastelloy X agitatorcontained 9% Mo and 0.6% W. The shaft and paddles of the agitator werethen shielded with {fraction (1/16)}″ nickel sheet using welding to cladall surfaces exposed to the reaction.

[0047] A standard sodium reduction process was used except as notedbelow. The lot was subjected to the agitator in the presence of puresodium to form tantalum powder. The tantalum powder was then washed withwater and subjected to acid treating and then steam drying and thenscreening to −100 mesh.

[0048] A sample from each batch was then submitted for glow dischargemass spec analysis. The two tables (Tables 1 and 2) below show thestarting analysis for the K₂TaF₇ and the final analysis of the tantalumrecovered. TABLE 1 K₂TaF₇ Spark Source Mass Spec (SSMS) Analysis (metalto salt basis) Sample Nb Mo W TOTAL Number (ppm) (ppm) (ppm) (ppm) 1 2’11 ≦2 <5 2 1 ’11 ≦2 <4 3 2 ’11 ≦2 <5 4 1 ’11 ≦2 <4

[0049] TABLE 2 Ta Powder Glow Discharge Mass Spec (GDMS) Analysis SampleNb Mo W TOTAL Number (ppm) (ppm) (ppm) (ppm) 5 1.4 0.38 0.27 2.05 6 1.20.30 0.50 2.00 7 1.0 0.25 0.29 1.54 8 1.1 0.15 0.28 1.53

[0050] As can be seen in the above tables, a high purity tantalum powdersuitable for electron beam melting into an ingot can be obtained andpurities on the order of 99.999% purity can be obtained by theprocessing shown in Example 1.

Example 3

[0051] Two distinct process methodologies were used. First, a 99.998%pure tantalum ingot was used which was subjected to three electron beamsmelts to produce a 12 inch nominal diameter ingot. The ingot wasmachined clean to about 11 ½ inch diameter and then heated in air toabout 260° C. for 4-8 hours. The ingot was then flat forged, cut, andmachined into slabs (approximately 4 inch by 10 inch with a length ofapproximately 28 inch to 32 inch) and then acid cleaned withHF/HNO₃/water solution. The slabs were annealed at 1050, 1150, and 1300°C. under vacuum of 5×10⁻⁴ Torr for 2 hours, then cold rolled into platestock of 0.500 and 0.250″ gauge. This cold rolling was accomplished bytaking a 4 inch thick by 10 inch wide by 30 inch long slab and rollingit perpendicular to the ingot axis at 0.200 inch per pass to 31 incheswide. The plate was then rolled parallel to the ingot axis at 0.100 inchper pass to 0.650 inch thick or 0.500 inch thick. Both rollings weredone on a 2-High breakdown rolling mill. Each of the plates were rolledby multiples passes of 0.050 inch per pass and then 0.025 inch per passwith final adjustments to meet a finish gauge of 0.500 inch plate or0.250 inch plate, using a four high finishing rolling mill. The plateswere then subjected to a final annealing at temperatures of from 950-1150° C.

[0052] The alternative process began with a 99.95% pure Ta which wassubjected to three electron beam melts to produce an ingot as describedabove prior to being forged. The ingot was then round forged using a GFMrotary forge to 4″ diameter after multiples passes of about 20%reduction in area per pass. From this intermediate stock, 4 billets(3.75″Ø×7″ long) were machined, and 2 billets (labeled A and B) wereannealed at 1050° C. while billets C and D remained unannealed. Next,the billets were upset forged to preforms of height of 2.5″, after whichpreforms A and C were annealed at 1050° C. The preforms were then clockrolled to a thickness of about 0.400″ to yield discs of a diameter ofapproximately 14″. This was accomplished by taking multiple passes of0.200 inch per pass to about 0.5250 inch thick. The discs were thenrolled to about 0.5 inch thick by multiple passes of 0.100 inch perpass. Then, the discs were clocked rolled on a four high finishing millin three passes of 0.050 inch, 0.025 inch, and 0.015 inch reductions perpass to yield a disc of about 0.400 inch thick by about 14 inchdiameter. A quarter of the disc was cut into four wedges and finalannealed at temperatures of 950-1100° C. Table 4 below summarizes thisprocessing.

[0053] Metallographic and texture analysis was conducted on longitudinalsections of the plate material (measurement face parallel to the finalrolling direction) and on radial sections of the forged and rolled discs(measurement face parallel to the radius of the discs).

[0054] Metallurgical Analysis

[0055] Grain size and texture were measured along the longitudinal orradial directions of samples taken from rolled plate and forged androlled discs, respectively. Grain size was measured using ASTM procedureE-112. Results from the annealing studies on products produced via theflat and round processes are given in Tables 3 and 4, respectively.Intermediate annealing treatments had no noticeable influence on thegrain size of the finished product. Also, for plate, the final grainsizes of 0.500 and 0.250″ thick tantalum were comparable. The onlyvariable found to significantly effect the grain size of the materialswas the final anneal temperature: the higher the final annealtemperature, the larger the resulting grain size.

[0056] In plate, grain sizes of ASTM 6.5-7.0 were measured in samplesfrom product annealed at 1000 and 950° C. However, each of these samplesshowed evidence of elongated and/or unrecrystallized regions at or nearthe surface, and recrystallization values were reported to be 98-99%.For plates annealed at 1050, 1100, and 1150° C., ASTM grain sizes rangedfrom 5.3 to 3.7, with all samples being 100% recrystallized.

[0057] For the round-processed discs, all samples were reported to be100% recrystallized, with the exception of Disc C annealed at 950° C.which was 99% recrystallized. Grain sizes of ASTM 7.1-7.2, 6.1-6.8, and5.9-5.9 were measured in the disc samples annealed at 950, 1000, and1050° C., respectively. Annealing at 1100° C. produced grain sizes ofASTM 4.0-4.5.

[0058] For both processes, these findings demonstrate that a fullyrecrystallized grain size of 50 μm or finer is achievable using eitherthe plate rolling or the billet forging process at a preferred finalanneal temperature of from about 950 to about 1050° C. Should theunrecrystallized areas be limited to only the surface regions of theplate, then they can be removed by machining.

[0059] Texture Measurement Technique: A limited number of samples(chosen based on metallurgical results) were used for texture analysis.Mounted and polished samples, previously prepared for metallurgicalanalysis, were employed as texture samples after being given a heavyacid etch prior to texture measurement. Orientation Imaging Microscopy(OIM) was chosen as the method of texture analysis because of its uniqueability to determine the orientation of individual grains within apolycrystalline sample. Established techniques such as X-ray or neutrondiffraction would have been unable to resolve any localized texturevariations within the thickness of the tantalum materials.

[0060] For the analysis, each texture sample was incrementally scannedby an electron beam (within an SEM) across its entire thickness; thebackscatter Kikuchi patters generated for each measurement point wasthen indexed using a computer to determine the crystal orientation. Fromeach sample, a raw-data file containing the orientations for each datapoint within the measurement grid array was created. These files servedas the input data for subsequently producing grain orientation maps andcalculating pole figures and orientation distribution functions (ODFs).

[0061] By convention, texture orientations are described in reference tothe sample-normal coordinate system. That is, pole figures are“standardized” such that the origin is normal to the plate surface, andthe reference direction is the rolling (or radial) direction; likewise,ODFs are always defined with respect to the sample-normal coordinatesystem. Terminology such as “a (111) texture” means that the (111)atomic planes are preferentially oriented to be parallel (and the (111)pole oriented to be normal) with the surface of the plate. In theanalyses, the crystal orientations were measured with respect to thesample longitudinal direction. Therefore, it was necessary to transposethe orientation data from the longitudinal to sample-normal coordinatesystem as part of the subsequent texture analysis. These tasks wereconducted through use of computer algorithms.

[0062] Grain Orientation Maps: Derived from principles of presentingtexture information in the form of inverse pole figures, orientationmaps are images of the microstructure within the sample where eachindividual grain is “color-coded” based on its crystallographicorientation relative to the normal direction of the plate of disc fromwhich it was taken. To produce these images, the crystal axes for eachgrain (determined along the longitudinal direction of the texture sampleby OIM) were tilted 90° about the transverse direction so to align thecrystal axes to the normal direction of the sample. Orientation mapsserve to reveal the presence of texture bands or gradients through thethickness on the product; in tantalum, orientation maps have shown thatlarge, elongated grains identified by optical microscopy can be composedof several small grains with low-angle grain boundaries.

[0063] Analysis of the Texture Results: OIM scans were taken along thethickness of each sample provided; for the 0.500″ plate samples,separate measurements were made for the top and the bottom portions ofthe plate and reported separately.

[0064] The orientation maps were visually examined to qualitativelycharacterize the texture uniformity through the sample thickness. Toattain a quantifiable description of the texture gradients and texturebands in the example materials, the measured EBSD data was partitionedinto 20 subsets, with each representing a 5% increment of depth throughthe thickness of the sample. For each incremental data set, an ODF wasfirst calculated, then (100) and (111) centroid intensities determinednumerically using techniques reported elsewhere. The equipment andprocedures described in S. Matthies et al., Materials Science Forum,Vol. 157-162 (1994), pp. 1647-1652 and S. Matthies et al., MaterialsScience Forum, Vol. 157-162 (1994), pp. 1641-1646 were applied, andthese publications are incorporated in their entirety herein byreference. The texture gradients were then described graphically byplotting the (100) and (111) intensities, as well as the log ratio ofthe (100):(111), as a function depth of the sample. These results areset forth in FIGS. 1(A and B) through FIGS. 11(A and B).

[0065] The heavy-gauge tantalum plate exhibited the most uniformthrough-thickness texture; the only sample containing texture bands wasthat processed with a slab anneal of 1300° C. and a final anneal of1000° C. In addition, the 0.500″ plate materials also had a relativeweak (most random) texture base on pole figure and ODF analysis.Compared to the heavy plate, the 0.250′ sheets contained a slight tomoderate texture gradient and some evidence of texture banding. Also,the thin-gauge plates showed a more defined (111) texture in the ODFsand an increased prominence of (100).

[0066] The greatest variability in terms of texture uniformity andbanding was found in the forged and rolled discs. Unlike themetallurgical properties, the texture of forged and rolled discs waseffected by the use of intermediate annealing. For discs A, B, and C,each of which were processed with one or two intermediate annealingsteps, the texture gradients ranged from negligible to strong (dependingto processing parameters) with slight—if any—banding. However, for discD, which was worked from ingot to final discs without intermediateannealing, the resultant product contained less desirable strong texturegradients and sharp texture bands. Similarly, disc C, which was alsoforged from unannealed billet but then annealed prior to cold rolling,also showed a strong texture gradient and banding in the sample finalannealed at 950° C. For disc C, increasing the final anneal temperatureto 1100° C. acted to diminish the gradient, eliminated the bands, butstrengthening the intensity of (100) texture component. These effectsfrom increasing final annealing temperatures were also evident, but to alesser degree, in both the other disc materials and the heavy gaugeplate.

[0067] From the microstructural and textural observations, the followingconclusions could be made regarding the optimum processing forfabricating tantalum sputtering targets:

[0068] For flat products, slab anneal temperatures preferably do notexceed 1150° C. (1050° C. is more preferred) and the final annealtemperature is preferably kept at 950-1000° C., more preferably 1000° C.The resulting product is characterized as having a recrystallizedaverage grain size of less 50 μm. and a (100) incremental intensity ofless than 15 random and a log ratio of (111):(100) of less than −4.0.

[0069] For round processing, billets preferably are annealed prior toforging and rolling into disc without use of an intermediate anneal atpreform level. Final anneal temperature is preferably 950-1100° C., andmore preferably is 1050° C. The resulting product is characterized ashaving a recrystallized average grain size below 50 μm, and a (100)incremental intensity of less than 15 random and a log ratio of(111):(100) of less than −4.0. TABLE 3 Metallurgical CharacteristicsProcess Slab Anneal Temperature (° C.) 1050 1150 1300 Gauge of PlateProduced from Slab .250¹¹ .500¹¹ .250¹¹ .500¹¹ .250¹¹ .500¹¹ ASTM ASTMASTM ASTM ASTM ASTM Grain % Grain % Grain % Grain % Grain % Grain %Plate Anneal Temperature (° C.) Size Recry, Size Recry, Size Recry, SizeRecry, Size Recry, Size Recry, 950 7.0 98 6.7 98 7.0 98 6.7 98 7.0 986.7 98 1000 6.5 99 6.5 99 6.5 99 6.5 98 6.5 99 6.5 98 1050 4.5 100 5.0100 4.5 100 5.0 99 4.5 100 5.3 100 1050 5.0 100 4.5 100 5.0 100 4.5 1005.0 100 4.5 100 1100 4.5 100 5.0 100 4.5 100 4.0 100 4.5 100 4.0 1001150 4.0 100 4.0 100 4.0 100 3.7 100 4.0 100 3.7 100

[0070] TABLE 4 BILLET A BILLET B BILLET C BILLET D PC. WEIGHT Anneal1050 C. Anneal 1050 C. Unannealed Unannealed 46.4 lbs 7″ Long UpsetForge Upset Forge Upset Forge Upset Forge 6.25″ 2.5″ Thick 2.5″ Thick2.5″ Thick 2.5″ Thick Diameter Anneal 1050 C. Anneal 1050 C. MachineMachine Machine Machine 42 lbs 6″ Diameter Clean Clean Clean CleanX-Roll to X-Roll to X-Roll to X-Roll to 15″ Gauge Gauge Gauge GaugeDiameter 0.400″ 0.400″ 0.400″ 0.400″ Saw Cut Saw Cut Saw Cut Saw Cut10.5 lbs/qtr. Quarters Quarters Quarters Quarters Anneal Study AnnealStudy Anneal Study Anneal Study ANNEAL ASTM GRAIN TEMP(° C.) SIZE(REX) 950 7.1 (100%) 7.2 (100%) 7.1 (99%)  7.2 (100%) 1000 6.1 (100%) 6.5(100%) 5.9 (100%) 6.8 (100%) 1050 5.8 (100%) 5.9 (100%) 5.9 (100%) 5.9(100%) 1100 4.5 (100%) 4.5 (100%) 4.5 (100%) 4.0 (100%)

[0071] Other embodiments of the present invention will be apparent tothose skilled in the art from consideration of the present specificationand practice of the present invention disclosed herein. It is intendedthat the present specification and examples be considered as exemplaryonly with a true scope and spirit of the invention being indicated bythe following claims.

What is claimed is:
 1. Tantalum metal having a purity of at least about99.995%, and an average grain size of about 125 microns or less.
 2. Thetantalum metal of claim 1, wherein said metal is fully recrystallized.3. The tantalum metal of claim 1, wherein said metal is at leastpartially recrystallized.
 4. The tantalum metal of claim 1, whereinabout 98% or more of said metal is recrystallized.
 5. The tantalum metalof claim 1, wherein about 80% or more of said metal is recrystallized.6. The tantalum metal of claim 1, wherein said metal has a) a texture inwhich a (100) pole figure has a center peak intensity less than about 15random or b) a log ratio of (111):(100) center peak intensities ofgreater than about −4.0, or c) both.
 7. The tantalum metal of claim 6,wherein said center peak intensity is from about 0 random to less thanabout 15 random.
 8. The tantalum metal of claim 6, wherein said centerpeak intensity is from about 0 random to about 10 random.
 9. Thetantalum metal of claim 6, wherein said log ratio is from greater thanabout −4.0 to about
 15. 10. The tantalum metal of claim 6, wherein saidlog ratio is from about −1.5 to about 7.0.
 11. The tantalum metal ofclaim 6, wherein said center peak intensity is from about 0 random toless than about 15 random, and said log ratio is from greater than about−4.0 to about
 15. 12. The tantalum metal of claim 1 having a purity offrom 99.995% to about 99.999%.
 13. A metal alloy comprising the tantalummetal of claim
 1. 14. A metal alloy comprising the tantalum metal ofclaim
 6. 15. A metal alloy comprising the tantalum metal of claim
 3. 16.A sputtering target comprising the tantalum metal of claim
 1. 17. Asputtering target comprising the tantalum metal of claim
 6. 18. Asputtering target comprising the tantalum metal of claim
 3. 19. Acapacitor can comprising the tantalum metal of claim
 1. 20. A capacitorcan comprising the tantalum metal of claim
 6. 21. A capacitor cancomprising the tantalum metal of claim
 3. 22. A resistive film layercomprising the tantalum metal of claim
 1. 23. A resistive film layercomprising the tantalum metal of claim
 6. 24. A resistive film layercomprising the tantalum metal of claim
 3. 25. An article comprising atleast as a component the tantalum metal of claim
 1. 26. An articlecomprising at least as a component the tantalum metal of claim
 6. 27. Anarticle comprising at least as a component the tantalum metal of claim3.
 28. Tantalum metal having a) an average grain size of about 50microns or less, or b) a texture in which a (100) pole figure has acenter peak intensity equal to or less than about 15 random or c) a logratio of (111):(100) center peak intensities of greater than about −4.0,or combinations thereof.
 29. The tantalum metal of claim 28 having anaverage grain size of from about 25 to about 50 microns.
 30. Thetantalum metal of claim 28 having a ratio of (111):(100) center peakintensities of greater than about −4.0.
 31. The tantalum metal of claim28, having both a) and b).
 32. The tantalum metal of claim 28, whereinsaid metal has purity of at least 99.995% tantalum.
 33. The tantalummetal of claim 28, wherein said metal has a purity of 99.999% tantalum.34. The tantalum metal of claim 28, wherein said metal is fullyrecrystallized.
 35. The tantalum metal of claim 32, wherein said metalis fully recrystallized.
 36. The tantalum metal of claim 33, whereinsaid metal is fully recrystallized.
 37. The tantalum metal of claim 28,wherein about 80% or more of said metal is fully recrystallized.
 38. Thetantalum metal of claim 28, wherein said center peak intensity is fromabout 0 random to about 15 random.
 39. The tantalum metal of claim 28,wherein said log ratio is from about −4.0 to about
 15. 40. An articlecomprising the tantalum metal of claim
 28. 41. An article comprising thetantalum metal of claim
 33. 42. A sputtering target comprising thetantalum metal of claim
 28. 43. A sputtering target comprising thetantalum metal of claim
 33. 44. A process for making the tantalum metalof claim 1, comprising reacting a salt containing tantalum with at leastone agent capable of reducing the salt to tantalum and a second salt ina reaction container having an agitator, wherein the reaction containeror a liner in the reaction container and the agitator or a liner on theagitator are made from a metal material having the same or higher vaporpressure of tantalum at the melting point of the tantalum.
 45. Theprocess of claim 44, wherein the salt containing tantalum comprises apotassium-fluoride tantalum and the agent comprises sodium.
 46. Theprocess of claim 45, wherein the second salt comprises sodium fluorideand/or sodium chloride.
 47. The process of claim 44, wherein prior toreacting said salt containing tantalum, said process comprising formingan acid solution comprising tantalum and impurities and conducting adensity separation of the acid solution containing tantalum from theacid solution containing the impurities; and crystallizing the acidsolution containing the tantalum to form the salt containing tantalum.48. The process of claim 47, wherein the tantalum and impurities arecrushed ore comprising tantalum and impurities.
 49. The process of claim47, wherein the acid solution comprising tantalum and impurities areformed by combining acid solution with crushed ore comprising tantalum.50. The process of claim 44, wherein the reaction occurs at about 800°C. to about 1100° C. while stirring.
 51. The process of claim 44,wherein the reaction container or liner and the agitator or liner on theagitator are metal-based, wherein said metal is nickel, chromium, iron,manganese, titanium, zirconium, hafnium, vanadium, technetium,ruthenium, cobalt, rhodium, palladium, platinum, or any combinationthereof.
 52. The process of claim 51, wherein the metal is nickel or anickel-based alloy.
 53. The process of claim 51, wherein the metal ischromium or a chromium-based alloy.
 54. The process of claim 51, whereinthe metal is iron or an iron-based alloy.
 55. The process of claim 44,further comprising recovering tantalum by dissolving the second salt inan aqueous solution.
 56. The process of claim 55, further comprisingmelting said recovered tantalum in a sufficient vacuum to removesubstantially any existing impurities in said recovered tantalum andobtain high purity tantalum.
 57. The process of claim 56, wherein thevacuum is 10⁻⁴ torr or more.
 58. The process of claim 56, wherein thepressure above the melted recovered tantalum is lower than the vaporpressures of substantially all of the impurities.
 59. The process ofclaim 56, wherein the impurities are removed by vaporization of theimpurities.
 60. The process of claim 56, wherein said melting isaccomplished by electron beam melting.
 61. The process of claim 56,wherein said melting is accomplished by vacuum arc remelt processing.62. The process of claim 56, wherein the high purity tantalum is allowedto form a solid and subjected to a rolling process, a forging process,or both.
 63. The tantalum metal of claim 1, wherein the tantalum metalhas a substantially fine and uniform microstructure.
 64. The tantalummetal of claim 1, wherein the tantalum metal has an average grain sizeof from about 25 to about 125 microns.
 65. The tantalum metal of claim64, wherein the tantalum metal has an average grain size of from about25 to about 100 microns.
 66. The tantalum metal of claim 65, wherein thetantalum metal has an average grain size of from about 25 to about 75microns.
 67. A process of making a sputtering target from tantalum metalhaving a purity of at least 99.995%, comprising: a) mechanically orchemically cleaning the surface of the tantalum metal, wherein thetantalum metal has a sufficient starting cross-sectional area to permitsteps b) through g); b) flat forging the tantalum metal into at leastone rolling slab, wherein the at least one rolling slab has sufficientdeformation to achieve substantially uniform recrystallization afterannealing in step d); c) mechanically or chemically cleaning the surfaceof the at least one rolling slab; d) annealing the at least one rollingslab at a sufficient temperature and for a sufficient time to achieve atleast partial recrystallization of the at least one rolling slab; e)cold or warm rolling the at least one rolling slab in both theperpendicular and parallel directions to the axis of the startingtantalum metal to form at least one plate; f) flattening the at leastone plate; and g) annealing the at least one plate to have an averagegrain size equal to or less than about 150 microns and a texturesubstantially void of (100) textural bands;
 68. The process of claim 67,wherein the tantalum metal has a purity of at least 99.999%.
 69. Theprocess of claim 67, wherein the flat forging occurs after step a) andafter the tantalum metal is placed in air for at least about 4 hours andfrom temperatures ranging from ambient to about 1200° C.
 70. The processof claim 67, wherein the cold rolling is transverse rolling at ambienttemperatures and the warm rolling is at temperatures of less than about370° C.
 71. The process of claim 67, wherein the annealing of the plateis vacuum annealing at a temperature and for a time sufficient toachieve recrystallization of the tantalum metal.
 72. A process of makinga sputtering target from tantalum metal having a purity of at least99.995%, comprising: a) mechanically or chemically cleaning the surfaceof the tantalum metal, wherein the tantalum metal has a sufficientstarting cross-sectional area to permit steps b) through i); b) roundforging the tantalum metal into at least one rod, wherein the at leastone rod has sufficient deformation to achieve substantially uniformrecrystallization after annealing in step d) or step f); c) cutting therod into billets and mechanically or chemically clean the surfaces ofthe billets; d) optionally annealing the billets to achieve at leastpartial recrystallization; e) axially forging billets into preforms; f)optionally annealing the preforms to achieve at least partialrecrystallization; g) cold rolling the preforms into at least one plate;and h) optionally mechanically or chemically clean the surfaces of theat least one plate; and i) annealing the at least one plate to have anaverage grain size equal to or less than about 150 microns and a texturesubstantially void of (100) textural bands, wherein annealing occurs atleast in step d) or f) or both.
 73. The process of claim 72, wherein thetantalum metal has a purity of at least 99.999%.
 74. The process ofclaim 72, wherein the round forging occurs after subjecting the tantalummetal to temperatures of about 370° C. or lower.
 75. The process ofclaim 72 wherein prior to axially the billets, the billets are annealed.76. The process of claim 72, wherein prior to cold rolling of thepreforms, the preforms are annealed.
 77. The process of claim 72,wherein the annealing of the preforms is vacuum annealing at asufficient temperature and for a time to achieve recrystallization. 78.The tantalum metal of claim 1, wherein said average grain size is fromabout 30 to about 125 microns.
 79. The tantalum metal of claim 1,wherein said average grain size is from about 30 to about 100 microns.80. The tantalum metal of claim 1, wherein said average grain size isabout 100 microns or less.
 81. The tantalum metal of claim 1, whereinsaid average grain size is about 50 microns or less.
 82. The tantalummetal of claim 1, wherein said average grain size is from about 25 toabout 100 microns.
 83. Tantalum metal having a purity of at least about99.995%, an average grain size of about 150 microns or less, and havinga) a texture in which a (100) pole figure has a center peak intensityless than about 15 random or b) a log ratio of (111):(100) center peakintensities of greater than about −4.0, or c) both.
 84. The tantalummetal of claim 83, wherein said metal is fully recrystallized.
 85. Thetantalum metal of claim 83, wherein said metal is at least partiallyrecrystallized.
 86. The tantalum metal of claim 83, wherein about 98% ormore of said metal is recrystallized.
 87. The tantalum metal of claim83, wherein about 80% or more of said metal is recrystallized.
 88. Thetantalum metal of claim 83, wherein said center peak intensity is fromabout 0 random to less than about 15 random.
 89. The tantalum metal ofclaim 83, wherein said center peak intensity is from about 0 random toabout 10 random.
 90. The tantalum metal of claim 83, wherein said logratio is from greater than about −4.0 to about
 15. 91. The tantalummetal of claim 83, wherein said log ratio is from about −1.5 to about7.0.
 92. The tantalum metal of claim 83, wherein said center peakintensity is from about 0 random to less than about 15 random, and saidlog ratio is from greater than about −4.0 to about
 15. 93. The tantalummetal of claim 83, having a purity of from 99.995% to about 99.999%. 94.A sputtering target comprising the tantalum metal of claim
 83. 95. Acapacitor can comprising the tantalum metal of claim
 83. 96. A resistivefilm layer comprising the tantalum metal of claim
 83. 97. An articlecomprising at least as a component the tantalum metal of claim
 83. 98.Tantalum metal having an average grain size of about 125 microns orless, and having 50 ppm or less metallic impurities.
 99. The tantalummetal of claim 98, further having 50 ppm or less O₂, 25 ppm or less N₂,or 25 ppm or less carbon, or combinations thereof.
 100. The tantalummetal of claim 98, having 10 ppm or less metallic impurities.
 101. Thetantalum metal of claim 100, further having 50 ppm or less O₂, 25 ppm orless N₂, or 25 ppm or less carbon, or combinations thereof.
 102. Thetantalum metal of claim 98, wherein said average grain size is fromabout 30 to about 125 microns.
 103. The tantalum metal of claim 98,wherein said average grain size is about 100 microns or less.
 104. Thetantalum metal of claim 98, wherein said average grain size is about 50microns or less.
 105. The tantalum metal of claim 98, wherein saidaverage grain size is from about 25 to about 100 microns.
 106. Thetantalum metal of claim 98, wherein said metal is fully recrystallized.107. The tantalum metal of claim 98, wherein said metal is at leastpartially recrystallized.
 108. The tantalum metal of claim 98, whereinabout 98% or more of said metal is recrystallized.
 109. The tantalummetal of claim 98, wherein about 80% or more of said metal isrecrystallized.
 110. The tantalum metal of claim 98, wherein said metalhas a) a texture in which a (100) pole figure has a center peakintensity less than about 15 random or b) a log ratio of (111):(100)center peak intensities of greater than about −4.0, or c) both.
 111. Thetantalum metal of claim 98, wherein said center peak intensity is fromabout 0 random to less than about 15 random.
 112. The tantalum metal ofclaim 98, wherein said center peak intensity is from about 0 random toabout 10 random.
 113. The tantalum metal of claim 98, wherein said logratio is from greater than about −4.0 to about
 15. 114. The tantalummetal of claim 98, wherein said log ratio is from about −1.5 to about7.0.
 115. The tantalum metal of claim 98, wherein said center peakintensity is from about 0 random to less than about 15 random, and saidlog ratio is from greater than about −4.0 to about
 15. 116. A sputteringtarget comprising the tantalum metal of claim
 98. 117. A capacitor cancomprising the tantalum metal of claim
 98. 118. A resistive film layercomprising the tantalum metal of claim
 98. 119. An article comprising atleast as a component the tantalum metal of claim 98.